JPH1151722A - Gas meter and its gas flow velocity measuring tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To regulate a distance between an ultrasonic transmitter/receiver to an optimum value and simply correct an error every tube by performing parallel displacement of an end member screwed on both the ends of a gas transmission passage in the longitudinal direction of the gas transmission passage by screw rotation. SOLUTION: A gas meter 1 introduces gas 100 from an introduction opening 105 to a chamber 101, gas flow is measured by a gas flow velocity measuring tube 2, and transmitted via a chamber 102 and a delivery opening 107. At this time, male screws 201a, 201b are arranged on both the ends of the gas transmission passage 108 of the gas flow velocity measuring tube 2 respectively, and female screws 202a, 202b screwed on the inner face side of ends 203a, 203b are screwed therewith. An ultrasonic wave is propagated in the gas transmission passage 108 by an ultrasonic transmitter/receiver 110, 111 held by holding members 204a, 204b provided on both end members to obtain measured data. In the case where the gas flow velocity measuring tube 2 is applied to a different kind of a gas meter, parallel displacement of end members 203a, 203b is performed in the longitudinal direction of the gas transmission passage 108 by screw rotation, and a distance between the ultrasonic transmitter/ receiver is regulated to an optimum value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a gas meter and a gas measuring tube thereof.

[0002]

2. Description of the Related Art As a gas meter which has been widely and conventionally used, there is a gas meter of a membrane type. This gas meter of a membrane type has a membrane which repeats vibration by the pressure of a gas flow inside a housing of the gas meter. In addition, this type of meter is a method of directly measuring the volume of the gas using a mechanical operation, that is, measuring the flow rate of the gas in response to the vibration of the film. Due to its simple and practical structure and high durability, it has been widely used. However, on the other hand, such a conventional gas meter of the membrane type has a disadvantage that it is difficult to adapt to recent digitization of the gas meter due to the characteristic of being a mechanical type as described above.

[0003] Here, the gas meter is roughly classified into a method of directly measuring the gas amount mechanically, such as the above-mentioned membrane gas meter, and a physical numerical value as a fluid of a gas flow such as a gas flow rate. Is measured, and a numerical value of the gas flow rate is calculated in accordance with the measured value.

That is, since the gas meter of the guess type handles the numerical value of the gas flow rate as a digital signal from the measurement stage, the gas flow rate value can be transmitted, processed, and stored as digital data even after the measurement. Therefore, it has the characteristic of being very well adapted to such a system for performing data management and the like, and is attracting attention as a particularly suitable technique for a gas meter which has recently been digitized.

Such an inferential gas meter measures the number of revolutions of a turbine caused by a gas flow using a device such as a rotary encoder, based on an ultrasonic measurement method using a propagation time difference between ultrasonic waves, and uses the measured value as a basis. Such as a turbine measurement method that calculates the value of the gas flow rate using a pressure difference method using a pressure difference between two points caused by the gas flow.
Several types of methods have been proposed, all of which have been attracting attention as being capable of accurately measuring the flow rate of gas with a continuous value.

Among them, the ultrasonic measurement method is particularly known as a technique suitable for a gas meter capable of accurately measuring a flow rate while having a small and relatively simple structure. As shown in FIG. 3, the gas meter of the ultrasonic measurement system divides an airtight chamber formed in an airtight structure into two chambers, that is, a first chamber 501 and a second chamber 502.
And the first chamber 5 connected to the gas pipe 504 on the upstream side.
01, an inlet 506 for introducing the gas 505, an outlet 508 connected to the gas pipe 507 on the downstream side to send out the gas 505 from the second chamber 502, From the first chamber 501 to the second
A cylindrical gas passage 509 for passing the gas 505 into the chamber 502; and a gas 505 passing through the gas passage 509.
In order to calculate the flow rate of the gas 505 based on the value of the flow rate, the center line 60 of the gas passage 509 is measured.
The main parts are formed by ultrasonic transmitters / receivers 510 and 511 which are arranged opposite to each other with a predetermined length in a direction parallel to zero.

[0007] The gas meter of the ultrasonic measurement system can accurately measure the gas flow rate with such a relatively simple structure.

[0008]

However, the gas conduction path 509 and the ultrasonic transmitters / receivers 510 and 511, which are the main parts of the measuring means used in the conventional ultrasonic measuring type gas meter, are mainly described. The so-called gas flow velocity measurement tube has an error in each tube as a product at the time of manufacture or the like due to the characteristic that the gas flow velocity can be accurately measured. That is, in most cases, this error is different for each of the gas flow velocity measuring tubes. This is due to an error due to the shape such as the length of the gas passage 509, the ultrasonic transmitter / receiver 510, 511
It is thought to be caused by various factors such as errors in the function of the gas flow meter, but once manufactured as a gas flow rate measuring tube, for example, the gas flow rate measuring tube is incorporated into a gas meter and a certification test is performed as a finished product. There is a problem in that if the product is certified as defective when received, even if it is manufactured as a perfect product, it must be disposed of.

In addition, in the case of an ultrasonic gas meter, generally, the performance (or specification) of an optimal gas flow rate measuring tube for measuring a gas flow rate as the gas meter is used.
Is fixedly determined in advance, so that a gas flow rate measuring tube that does not match this or has a large error cannot be used.

Therefore, it goes without saying that the gas flow rate measurement tube manufactured to meet one type (for example, the number as a gas meter, etc.) of course is determined to be defective as described above. Can be used only for the gas meter. For this reason, various types of gas flow velocity measurement tubes must be prepared so as to respectively meet the demands of diversifying gas meter specifications, resulting in a problem that extremely complicated diversification of performance or specifications is caused. .

The present invention has been made to solve such a problem. The present invention can be applied to a case in which an error varies between individual gas flow rate measuring tubes.
The error can be corrected by an extremely simple and highly practical method, and the gas flow rate measuring tube or gas meter using it has a performance that meets the original ideal specifications without having to dispose as in the past. It is an object of the present invention to provide a technology that can realize the above. Another object of the present invention is to provide a technology that can meet a variety of required performances with one type of gas flow velocity measurement tube or a gas meter using the same.

[0012]

First, a gas meter according to the present invention comprises an airtight chamber formed in an airtight structure, a partition for dividing the airtight chamber into two chambers, a first chamber and a second chamber, An inlet connected to an upstream gas pipe for introducing gas into the first chamber, an outlet connected to a downstream gas pipe for sending gas from the second chamber, and penetrating the partition wall. And a gas passage for measuring the flow rate of the gas passing through the gas passage and calculating the flow rate of the gas by measuring the flow rate of the gas passing through the gas passage. In a gas meter having a flow rate calculating means, a gas conducting path formed in the cylindrical shape and having male threads at both ends thereof, and a female thread screwed to the male thread is formed in a cylindrical shape. A cylindrical end member engraved on the inner surface side of Two end members respectively screwed into the male threads at both ends of the passage, and holding members attached to the two end members so as to face each other on a line passing through the cylinder of the gas conducting passage. In addition, a gas flow rate measuring tube including a pair of two ultrasonic transmitters / receivers for transmitting ultrasonic waves so as to penetrate through the cylinder of the gas conducting path is provided.

That is, according to the technique of the present invention, since one end member is screwed into each of the male screws at both ends of the gas passage, each screw is screwed to both ends of the gas passage. The two end members can be translated in the longitudinal direction of the gas passage by rotating the screw.

By moving the two end members at both ends of the gas passage in parallel in this manner, the distance between the ultrasonic transmitter / receiver and the ultrasonic transmitter / receiver held one by one at each of the two end members can be reduced. , So you can fine-tune it to the optimal value,
It is possible to realize the gas flow rate measuring tube with the optimum performance for the specifications of each gas meter. As a result, even if an error occurs, a gas flow rate measuring tube having a performance conforming to the original ideal specification can be realized extremely easily without disposal as in the related art.

Further, according to the technique of the present invention, the distance between a pair of ultrasonic transmitters / receivers opposed to each other can be changed to an optimum value at any time. In addition to the effect of adjusting errors in a single lot of manufactured products, to realize a gas flow rate measurement tube or a gas meter using the same that can support multiple types, that is, various types of required performance, with the same type of component configuration Can also.

That is, a plurality of gas flow rate measuring tubes having the same type of components or gas meters provided with the same are manufactured in advance, and the gas flow rate measuring tubes are provided with the above-mentioned performance so as to conform to the specifications required for each type of gas meter. By changing the distance between the two ultrasonic transmitters / receivers to optimal values, it is possible to respond to various types of required performance.

Secondly, in the gas meter according to the present invention, in the gas meter according to the first aspect, the female screw of the end member and the male screw of the gas passage are formed as screws having different pitches at both ends. It is a gas meter characterized by the above. In this manner, the pitch of the screw at one end of the gas passage is made coarse, and the pitch of the screw at the other end is made fine, so that the pair of ultrasonic oscillators / vibrators can be used. When adjusting (changing) the distance between them relatively large, adjust the distance at the end provided with the coarse screw,
In the case of finer adjustment, since the adjustment can be performed at the end provided with the finer screw, the structure of the gas meter that can perform the adjustment more effectively and easily can be realized.

Third, an airtight chamber formed in an airtight structure,
A partition wall for dividing the airtight chamber into a first chamber and a second chamber, an inlet connected to an upstream gas pipe for introducing gas into the first chamber, and a gas pipe connected to a downstream gas pipe. A gas meter having an outlet for sending gas from the second chamber, the gas meter being disposed so as to penetrate the partition wall, and allowing the gas fluid to pass from the first chamber to the second chamber; In a gas flow rate measuring tube for measuring a flow rate, a gas conducting path formed in the cylindrical shape and provided with a male screw at each end of the cylinder, and a female screw screwed to the male screw are provided. A cylindrical end member disposed on the inner surface side of the cylinder, two end members each of which is screwed into each of the male threads at both ends of the gas passage, and the gas passage; So as to face each other at a position on a line passing through the center of the cylinder of A pair of ultrasonic transmitters / receivers, each of which is held at a central portion of each of the two end members and transmits ultrasonic waves through the central portion of the cylinder of the gas conducting path. It is a gas flow velocity measuring tube characterized by the above.

That is, the gas flow rate measuring tube according to the third aspect is a gas flow rate measuring tube used in the gas meters according to the first and second aspects, and is a product before being incorporated in a gas meter housing or the like. It is a gas flow rate measurement tube in the case where it is treated as. Therefore, the same effect as described above can be obtained by incorporating the gas flow rate measuring tube described in the third aspect into a gas meter. In addition, in terms of the effect of the gas flow velocity measurement tube itself, errors and performance of the gas flow velocity measurement tube can be inspected before being incorporated into the gas meter, so that it has been assembled as a conventional finished product. It is also possible to eliminate the inconvenience that quality inspections and certifications are performed later and the products are determined to be defective and must be disposed of.

Fourth, in the gas flow velocity measuring tube according to the third aspect, the female screw of the end member and the male screw of the gas conducting path are formed as screws having different pitches at both ends. It is a gas flow velocity measuring tube characterized by the following. In the technique of the fourth aspect, similarly to the technique of the second aspect, the pitch of the thread at one end of the gas passage is made coarse and the pitch of the thread at the other end is fine. In the case where the distance between the pair of ultrasonic transmitters / receivers is relatively large (changed), the distance between the pair of ultrasonic transmitters / receivers is adjusted with the end provided with the coarse screw, and further fine adjustment is performed. In this case, since the adjustment can be performed at the end provided with the fine screw, the structure of the gas flow velocity measuring tube that can perform the adjustment more effectively and easily can be realized.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a gas meter according to the present invention and a gas flow rate measuring tube used for the same will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing an outline of the structure of a gas meter according to the present invention and a gas flow rate measuring tube used therein. FIG. 1B is a cross-sectional view taken along the line AA ′ in the gas flow velocity measuring tube of FIG. FIG. 2 is a diagram showing an example of a case where the gas flow velocity measuring tube is handled as a single component.

A gas meter 1 and a main part of a gas flow rate measuring tube 2 used for the gas meter 1 include a partition 103 for dividing an airtight chamber formed into an airtight structure into two chambers, a first chamber 101 and a second chamber 102, and an upstream side. An inlet 105 connected to the gas pipe 104 for introducing the gas 100 into the first chamber 101; an outlet 107 connected to the downstream gas pipe 106 to send the gas 100 from the second chamber 102;
A cylindrical gas passage 108 that is arranged to penetrate the partition 103 and allows the gas 100 to pass from the first chamber 101 to the second chamber 102;
The flow velocity of the gas 100 passing through the
And a gas flow rate calculating means 109 for calculating the flow rate of the gas. The gas passage 108 is formed in a cylindrical shape and has male threads 201a and 201b at both ends in the longitudinal direction.
08. Further, the male screws 201a, 2
01b, cylindrical end members 203a, 203 having female threads 202a, 202b screwed into the inner surface of the cylinder.
b, two end members 203a and 203b respectively screwed into the male screws 201a and 201b at both ends of the gas passage 108, and the gas passage 108
Each of the two end members 203a, 203b is provided with one end member 203a,
A pair of two ultrasonic transmitters / receivers, which are held by holding members 204a and 204b attached to 203b and are opposed to each other so as to propagate ultrasonic waves through the center of the cylinder of the gas passage 108. 110 and 111 are provided. Of the above, the gas passage 108, the end member 203
The main parts of the gas meter 1 and the gas flow velocity measuring tube 2 according to the present invention are constituted by a, 203b, holding members 204a, 204b, and ultrasonic oscillators / vibrators 110, 111. The circuit itself of the gas flow rate calculating means for calculating the gas flow rate based on the data measured by the ultrasonic transmitters / receivers 110 and 111 is the same as the conventional circuit system for calculating the gas flow rate. In this specification, the details are omitted for simplification of the description.

Further, the above-mentioned end members 203a, 203
The female screws 202a and 202b of the 03b and the male screws 201a and 201b of the gas passage 108 are formed as screws having different pitches between the end members 203a and 203b at both ends. That is, the male screw 201a and the female screw 202a on the end member 203a side are fine pitch screws, and the male screw 201b and the female screw 202b on the other end member 203b side are coarse pitch screws, so that they are opposed to each other. Two ultrasonic transmitter / receiver 11
A large change in the distance between 0 and the ultrasonic transmitter / receiver 111 is adjusted by rotating the end member 203b side with respect to the gas passage 108, and fine adjustment is performed by rotating the end member 203a side. can do. Such a method of using different pitches with different densities is, for example, when the distance is adjusted so that the gas flow rate measuring tube 2 is applied to a different type of gas meter, the distance is generally changed relatively largely. It is necessary to rotate the end member 203b on the coarse pitch side to roughly adjust it, and further adjust the fine pitch end member 203a when adjusting the error on the same specification. By rotating and making further fine adjustments, the optimum adjustment can be performed quickly and effectively.

The above-mentioned gas flow velocity measuring tube can be formed so as to be able to be handled as a single component, and can be used by being incorporated into a predetermined gas meter housing. An example of such a case is shown in the perspective view of FIG. As can be clearly seen from FIG. 2, the gas flow rate measuring tube has a flange 300 disposed substantially at the center of the gas passage 108 and the gas meter 1
Can be attached to a mounting hole or the like prepared in advance on the partition wall 103. Moreover, the holding members 204a, 204b
(However, 204b is not shown in FIG. 2 because it is not visible in FIG. 2). Since the gas 100 is formed in such a shape, the flow of the gas 100 passing therethrough can be rectified to further contribute to accurate measurement.

Further, the ultrasonic transmitter / receiver 110,
Usually, wirings 301a and 301b for applying a voltage to them and making them function are connected to 111. Therefore, for example, when connecting the ultrasonic oscillators / vibrators 110 and 111 to a drive circuit and performing a performance test on the gas flow velocity measuring tube, it is necessary to use the 203
When the length of the gas flow velocity measuring tube is adjusted by rotating a and 203b, if the end member 203a or 203b is rotated at this time, the wires 301a and 301b connected thereto are twisted. It is inconvenient. If it is necessary to avoid such inconvenience, for example, the screws 201a and 201b are formed as pairs of opposite screws, and the end members 203a and 203b are not rotated and the gas passage 10 is not rotated.
8 may be rotated.

[0026]

As described in the detailed description above, according to the present invention, even if an error varies among individual gas flow velocity measuring tubes, the error can be reduced to a very simple practicality. It is possible to realize a gas flow rate measuring tube or a gas meter using the gas flow rate measuring tube which can be corrected by a high technique and has a performance conforming to the original ideal specification without disposing as in the past. Also, since one kind of gas flow velocity measuring tube or gas meter using it can be readjusted by an extremely simple method,
A single type of gas flow velocity measuring tube can be adapted to various types of required performance.

[Brief description of the drawings]

FIG. 1 is a diagram showing an outline of the structure of a gas meter according to the present invention and a gas flow velocity measuring tube used therein.

FIG. 2 is a diagram showing an example of a case where a gas flow velocity measuring tube is handled as a single component.

FIG. 3 is a diagram showing an outline of the structure of a conventional ultrasonic measurement type gas meter.

[Explanation of symbols]

1: gas meter, 2: gas flow rate measuring tube, 100:
Gas, 108: gas conducting path, 203a, 203b: end member, 204a, 204b: holding member

Claims (4)

[Claims] An airtight chamber formed in an airtight structure, a partition for dividing the airtight chamber into two chambers, a first chamber and a second chamber,
An inlet connected to an upstream gas pipe for introducing gas into the first chamber; and a second port connected to a downstream gas pipe for introducing the gas.
An outlet for delivering gas from the chamber, a gas passage arranged to penetrate the partition wall, a gas passage for passing the gas fluid from the first chamber to the second chamber, and a gas passage for passing the gas passage. A gas meter having gas flow rate calculating means for calculating a flow rate of the gas by measuring a flow velocity, wherein the gas flow path is formed in a cylindrical shape, and male threads are provided at both ends of the cylinder, respectively. A female end screw engaged with a male screw is a cylindrical end member engraved on the inner surface side of the cylinder, and two end members respectively screwed to the male screws at both ends of the gas passage. Each of the two end members is held by a holding member attached to each of the two end members so as to face each other on a line passing through the cylinder of the gas passage. Two pairs of supersonic waves Wave onset /
A gas meter, comprising: a gas flow rate measurement tube having a vibration receiver. 2. The gas meter according to claim 1, wherein the female threads of the end members at both ends and the male threads of the gas conduction path screwed thereto are screws having different pitches at the both ends. Gas meter. 3. An airtight chamber formed in an airtight structure, a partition dividing the airtight chamber into a first chamber and a second chamber, and a gas pipe connected to an upstream gas pipe to introduce gas into the first chamber. The gas inlet having an inlet and a gas outlet connected to a gas pipe on the downstream side and sending out gas from the second chamber is disposed so as to penetrate through the partition wall, and the first chamber is connected to the second chamber from the first chamber. A gas flow path tube for measuring a gas flow velocity of the gas fluid by allowing the gas fluid to pass through the two chambers, the gas flow path being formed in a cylindrical shape, and having male threads disposed at both ends of the cylinder. And a female screw screwed to the male screw is a cylindrical end member disposed on the inner surface side of the cylinder, one for each of the male screws at both ends of the gas conducting path. Two end members to be screwed together, and a central portion of a cylinder of the gas passage. Two at the center of each of the two end members so as to be opposed to each other at a position on a line passing through, and to transmit ultrasonic waves through the center of the cylinder of the gas conducting path. And a pair of ultrasonic oscillators / vibrators. 4. The gas flow rate measuring tube according to claim 3, wherein the internal thread of the end member and the external thread of the gas passage are:
A gas flow rate measuring tube, wherein the two ends are formed as threads having different pitches.